Biod 171 Final Exam Study

What is the purpose of the quadrant streak approach? {Ans: The purpose of this method is to generate an individual colony so that a single (pure) bacterial sample can be picked from the plate.}What is the distinguishing feature of dark field microscopy? {Ans: Unlike bright field or phase contrast microscopy where light passes directly through the sample, dark field microscopy reflects light off of the specimen at an angle. The resulting image is an exceptionally dark background and a vibrant specimen.}What must happen before viral replication of its genome can occur? {Ans: For all viruses, the genome is replicated following attachment and entry, never before.}If you wish to increase the amount of light going into a microscope, what part would you adjust? {Ans: The iris diaphragm controls the amount of light that passes through the sample and into the objective lens. Thus, as you open the iris more light is permitted to pass through to illuminate the sample.}How does the viral envelope both aid in cell entry as well as hide it from being detected by the immune system? {Ans: The viral envelope contains the necessary proteins required for interaction with host cells. As the